Citric Acid → Methyl 3-chloro-5-cyclopropylbenzoate

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 3-chloro-5-iodobenzoate (0.5 g, 1.69 mmol) in THF (5 mL) were added cyclopropylzinc(II)bromide (3.71 mL, 1.86 mmol), PEPPSI-IPr (22.9 mg, 33.7 μmol, CAS RN 905459-27-0) and 1,3-dimethyl-2-imidazolidinone (DMI) (1 mL) and the turbid light brown solution was stirred at 50° C. for 2.25 hours. The reaction mixture was poured on 10% aqueous citric acid solution and EtOAc and the layers were separated. The aqueous layer was extracted twice with EtOAc. The organic layers were washed with brine, dried over MgSO4, filtered, treated with silica gel and evaporated. The compound was purified by silica gel chromatography on a 50 g column using an MPLC (Flasmaster) system eluting with a gradient of n-heptane:EtOAc (100:0 to 70:30). The obtained fraction (light yellow oil, 315 mg) was dissolved in THF (5 mL), to the clear solution were added cyclopropylzinc(II) bromide (3.71 mL, 1.86 mmol), PEPPSI-IPr (22.9 mg, 33.7 μmol, CAS RN 905459-27-0) and 1,3-dimethyl-2-imidazolidinone (DMI) (1 mL) and the reaction mixture was heated at 50° C. for 2.25 hours. The reaction mixture was poured on 10% aqueous citric acid solution and EtOAc and the layers were separated. The aqueous layer was extracted twice with EtOAc. The organic layers were dried over MgSO4, filtered, treated with silica gel and evaporated. The compound was purified by silica gel chromatography on a 10 g column using an MPLC (ISCO) system eluting with a gradient of n-heptane:EtOAc (100:0 to 40:60) to give the title compound as a light brown oil (0.225 g; 63%) containing 3,5-dicyclopropyl-benzoic acid methyl ester.

Provenance & Evidence